Autologous Stem Cell Mobilization in the Age of Plerixafor.

BACKGROUND: Autologous stem cell transplantation remains important in the treatment of myeloma and relapsed lymphoma. Plerixafor has been shown to significantly enhance stem cell mobilization but is very expensive.

PATIENTS AND METHODS: We evaluated plerixafor use in the 3-year period after its approval in December 2008.

RESULTS: A total of 277 patients with myeloma and lymphoma had stem cell mobilization; 97.5% were successfully mobilized, including 41.5% who received plerixafor. Plerixafor was generally used for rescue after suboptimal granulocyte-colony stimulating factor (G-CSF) mobilization ("just in time") or for remobilization after an unsuccessful attempt with chemotherapy plus G-CSF. In addition, 10% of patients received planned G-CSF plus plerixafor because of high risk factors for inadequate collection. Rescue plerixafor was more effective in patients with myeloma than lymphoma as after 1 dose of plerixafor; 85% versus 55% collected a minimum number of stem cells (2 × 10E6 CD34 cells/kg) for 1 transplant and 51% versus 15% collected > 5 × 10E6 CD34 cells/kg. After transplantation, there were no significant differences in engraftment as a consequence of plerixafor use. Among all patients, there were less platelet transfusions in patients provided ≥ 3.5 × 10E6 CD34(+) cells/kg.

CONCLUSION: With the judicious use of plerixafor, nearly all patients can collect enough stem cells to proceed to transplantation. Further studies, including hematologic tolerance to posttransplantation therapy, are required to determine the cost-effectiveness of using plerixafor to convert adequate to more optimal mobilizers.